See also How to make your own jacks.
Traditionally players drew throwing circles in the dirt using a toe, a finger, or a stick. Some liked to carry a special circle-drawing tool.
Plastic circles were introduced about 2005 and quickly became popular. Today, you can buy circles at the Petanque America web site. They work well, but they’re expensive to buy and expensive to ship. That’s why players often choose to to make their own.
How to make a throwing circle from plastic tubing
FIPJP rules specify that the (inside) diameter of a plastic throwing circle should be 50 centimeters. Using this number and the magic of π we get a circumference of 157 centimeters. That’s 62″, or almost exactly 5’2″.
My local hardware store sells plastic tubing for about $0.50 per foot. So I bought 6 feet ($3.00).
I cut off a 62″ length of tubing, and also a short section of tubing about 2 inches long. I split the short section in half lengthwise and used one of the halves as a splint to join the two open ends of the 62″ length, so the tubing formed a closed circle. Voila, une rond.
Unfortunately, the tubing that I had bought had been coiled into small tight loops at the hardware store. The tubing always wanted to return to those tight little loops and my circle refused to be truly circular.
I went back to the hardware store and found some tubing that had been coiled into larger, looser loops. It was made out of (I think) 3/8″ PVC. When I made a throwing circle from it, the shape was very nearly an exact geometric circle.
Ignoring the failed first prototype, the total cost for my home-made circle was about $3.00.